The present invention relates to ambient samplers for monitoring power plant stack emissions, ambient emissions and other environmental fallout. More particularly, the invention concerns apparatus for protecting the collection surface of such devices from rain.
Apparatus for monitoring environmental fallout generally comprises a collection surface for the collection of fallout from the environment over time. The surface can comprise any suitable material, such as a paper substrate that can then be removed from the collection device and analyzed. One type of ambient sampler has a collection disk that rotates over time. For example, the disk may rotate one revolution each twenty-four hours. A collection opening allows fallout to enter the apparatus and to settle on the collection disk. Such apparatus allows a time resolvable record to be established of "fallout emissions" from industrial processes such as power plant stacks.
While such apparatus functions suitably under dry conditions, the entry of rain water into the collection opening can wash away the collected samples and interfere with accurate analysis of fallout emissions. This is a particular problem in wet climates, such as on the island of Hawaii where it rains frequently and heavily each day.
It would be advantageous to provide automatic and self-restoring protection from rain in an ambient sampler. It would be further advantageous if apparatus could be provided to afford rain protection without the need for any external power source. The present invention provides apparatus for protecting an ambient sampler from rain, having the aforementioned and other advantages.